1. Field of the Inventions
The present inventions relate generally to earstems for eyewear. More specifically, the present inventions relate to methods and apparatuses for providing a tunable multiflex earstem that utilizes one or more flex zones or points to enable an eyeglass to comfortably fit a variety of head sizes and shapes.
2. Description of the Related Art
A wide variety of improvements have been made in recent years in the eyewear field, particularly with respect to eyewear intended for use in active sports or as fashion sunglasses. These eyewear designs accomplish a variety of functional advantages, such as maximizing interception of peripheral light, reducing optical distortion and increasing the wearer's comfort level, compared to previous active sport eyewear.
Lens geometry has also been the subject of a variety of innovations. The unitary lens of the Blades® eyewear incorporates the cylindrical geometry disclosed, for example, in U.S. Pat. No. 4,859,048, issued to Jannard. This geometry allows the lens to closely conform to the wearer's face and intercept light, wind, dust, etc. from directly in front of the wearer (anterior direction) and peripherally (lateral direction). See also U.S. Pat. No. 4,867,550 to Jannard (toroidal lens geometry).
In another important areas, eyeglass fit and comfort has generally been addressed by varying eyeglass frame size, minimizing eyeglass weight, modifying the manner in which earstems engage ears of the wearer, and utilizing nosepiece and ear-contacting materials that are comfortable for extended use, to name a few.
Eyeglass fit and comfort has been determined at least in part due to the material of which the eyeglass is made. For example, plastic or injection molded frame eyeglasses are often more flexible than metal frame eyeglasses, and therefore could provide lighter overall weight and greater flexibility than a metal frame eyeglass. Although metal frame eyeglasses have been improved in some ways, such as incorporating a spring overextension feature into the hinge connection of the earstem with the frame, the spring overextension feature is primarily useful in facilitating placement and mounting of the eyeglass on the head of the wearer. Such features may have moderately improved the flexibility and fit of plastic and metal frame eyeglasses; however, rigid frames and earstems do not provide any dynamic adjustment or flexibility. As such, prior art eyeglass designs do not adjust well over a range of head sizes and shapes.